Well-Architected Framework — 6 Pillars

The 6 pillars

Pillar	Core question	Covers
1. Operational Excellence	How do we RUN it well?	Runbooks, CloudWatch, CI/CD, automation, learn from failure
2. Security	How do we PROTECT it?	IAM least privilege, KMS encryption, WAF, CloudTrail audit, shared responsibility
3. Reliability	How do we KEEP it UP?	Multi-AZ, Auto Scaling, backups (PITR), failover, health checks, RPO/RTO
4. Performance Efficiency	How do we do it FAST/LEAN?	Right-sizing, serverless, autoscaling, CloudFront caching, managed services
5. Cost Optimization	How do we make it CHEAP?	Spot, Reserved/Savings Plans, rightsizing, stop idle, Cost Explorer
6. Sustainability (added 2021)	How do we keep the PLANET happy?	Efficient hardware, serverless, right-sizing, clean-energy regions

Exam hooks (one per pillar)

Operational Excellence = CloudWatch, runbooks, CI/CD
Security              = IAM, KMS, WAF
Reliability           = Multi-AZ, backups
Performance Efficiency = right-size, serverless, caching
Cost Optimization     = Spot, RI/Savings, idle cleanup
Sustainability        = added 2021, environment

Key design principles (recognition level)

• OpEx: infra as code (CloudFormation), frequent small reversible changes, anticipate failure
• Security: strong identity (least privilege), traceability (CloudTrail), all layers, automate
• Reliability: auto-recover, test recovery, horizontal scale, stop guessing capacity
• Perf: managed services, go global (regions), serverless, experiment
• Cost: consumption model (pay-as-you-go), measure efficiency, managed services over undifferentiated work
• Sustainability: efficient hardware, right-size, serverless

Exam patterns

• “Multi-AZ + backups” → Reliability
• “IAM + encryption” → Security
• “right-sizing + Spot” → Cost Optimization
• “CloudWatch + runbooks” → Operational Excellence
• “serverless + caching” → Performance Efficiency
• “added in 2021” → Sustainability

Related

• [[aws/index]]
• [[aws/shared-responsibility/index]]